JP2018181848A - Insulative porous layer for nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulative porous layer for a nonaqueous electrolyte secondary battery, which is useful as a member of a nonaqueous electrolyte secondary battery superior in cycle characteristics.SOLUTION: An insulative porous layer for a nonaqueous electrolyte secondary battery comprises a thermoplastic resin and has a porosity of 25% or more and 80% or less. In the insulative porous layer, the rate of a quantity of displacement in the 10-th loading-unloading cycle to a quantity of displacement in the 50-th loading-unloading cycle is 100% or more and less than 115%.SELECTED DRAWING: None

Description

  The present invention also relates to an insulating porous layer for a non-aqueous electrolyte secondary battery, a laminated separator for a non-aqueous electrolyte secondary battery, a member for a non-aqueous electrolyte secondary battery, and a non-aqueous electrolyte secondary battery.

  BACKGROUND OF THE INVENTION Non-aqueous electrolyte secondary batteries such as lithium secondary batteries are currently widely used as batteries for use in devices such as personal computers, mobile phones and portable information terminals, or as batteries for vehicles.

  As a separator in such a non-aqueous electrolyte secondary battery, there is known a laminated separator in which a porous layer containing a filler and a resin is laminated on at least one surface of a porous base mainly composed of polyolefin. There is.

  For example, in Patent Document 1, a microporous film having compression characteristics such as a specific amount of compressive deformation and an amount of compressive deformation increase and a specific porosity (porosity) is for a battery having excellent output characteristics and durability of the battery. It is disclosed that it can be used as a separator.

JP, 2012-87223, A (May 10, 2012 release)

  The “compression deformation amount” described in Patent Document 1 is a deformation amount of the microporous film when a load is applied to the microporous film at the first time in the case where the loading-unloading cycle is repeated. “Compression deformation increase amount” described in Patent Document 1 corresponds to the short-term charge and discharge cycle, and the amount of deformation of the microporous film at the time of applying the load for the first time and the microporous at the time of applying the load for the tenth time. It is a value based on the difference with the deformation amount of the quality film.

  However, Patent Document 1 does not disclose any increase rate of “the amount of compressive deformation” when the load-unload cycle is performed more than ten times, which corresponds to a long charge / discharge cycle, In addition, the relationship between the compression characteristics and the cycle characteristics is not disclosed at all. And the conventional battery separator which is disclosed by patent document 1 was not enough as the battery output characteristic at the time of repeating a long charge / discharge cycle, ie, cycle characteristics.

The present invention includes the inventions shown in the following [1] to [5].
[1] An insulating porous layer for a non-aqueous electrolyte secondary battery containing a thermoplastic resin, comprising:
The porosity is 25% or more and 80% or less,
An insulating porous layer for a non-aqueous electrolyte secondary battery, wherein the ratio of the displacement in the 10th load-unload cycle to the displacement in the 50th load-unload cycle is 100% or more and less than 115%. .
[2] A laminated separator for a non-aqueous electrolyte secondary battery, comprising a polyolefin porous film and the insulating porous layer for a non-aqueous electrolyte secondary battery according to [1].
[3] A positive electrode, the insulating porous layer for a non-aqueous electrolyte secondary battery according to [1], or the laminated separator for a non-aqueous electrolyte secondary battery according to [2], and a negative electrode A member for a non-aqueous electrolyte secondary battery which is disposed in order.
[4] A non-aqueous electrolyte secondary battery comprising the insulating porous layer for a non-aqueous electrolyte secondary battery according to [1] or the non-aqueous electrolyte secondary battery according to [2] .

  The insulating porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention is the charge and discharge in a non-aqueous electrolyte secondary battery including the insulating porous layer for the non-aqueous electrolyte secondary battery. When the cycle is repeated, the capacity retention rate is high, and the cycle characteristics are excellent.

It is a schematic diagram which shows the loading-unloading cycle in this invention.

  Although the following describes one embodiment of the present invention, the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be combined as appropriate. The resulting embodiments are also included in the technical scope of the present invention. In addition, unless otherwise indicated in this specification, "A-B" showing a numerical range means "A or more, B or less".

[Embodiment 1: Insulating porous layer for non-aqueous electrolyte secondary battery]
The insulating porous layer for a non-aqueous electrolyte secondary battery (hereinafter, also simply referred to as "porous layer") according to Embodiment 1 of the present invention is an insulating film for a non-aqueous electrolyte secondary battery containing a thermoplastic resin. A porous layer having a porosity of 25% or more and 80% or less, and a ratio of a displacement amount in a tenth load-unload cycle to a displacement amount in a 50th load-unload cycle (hereinafter simply referred to as “ Also referred to as “displacement rate” is 100% or more and less than 115%.

  The “displacement amount” and “displacement rate” in the load-unload cycle of the insulating porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention can be measured by the method described below.

  As shown in FIG. 1, a laminated separator for a non-aqueous electrolyte secondary battery formed by laminating a porous layer or a porous layer on a base material is cut out into 1 cm square to obtain a measurement sample 2. The sample 2 for measurement is fixed on a sample base using an adhesive (water paste), and a flat indenter 1 (made of diamond) having a diameter of 50 μm is loaded from the surface of the sample 2 for measurement at a speed of 0.4877 mN / sec. Push in to a depth of 1 mN (load). Immediately after that, the planar indenter 1 is pulled back to the position of the surface of the sample 2 for measurement where the load is 0 mN at a speed of 0.4877 mN / sec without hold time (unloading). Here, “load” means the magnitude of stress that the planar indenter 1 receives from the measurement sample 2 when the planar indenter 1 is pressed into the measurement sample 2.

  A load is applied to the measurement sample 2 described above and immediately thereafter, a cycle for removing the load (herein referred to as a load-unload cycle) is repeated 50 times. In the measurement sample 2 in the 10th load-unload cycle, the distance between the depth of depression of the plane indenter 1 and the position of the surface of the measurement sample 2 at which the load is 0 mN when the plane indenter 1 is pulled back. Measure Let the said distance be the displacement amount (unit: micrometer) in the 10th load-unload cycle. Similarly, in the sample 2 for measurement in the 50th load-unload cycle, the depth at which the flat indenter 1 is pushed in and the position of the surface of the sample 2 for measurement that results in a load of 0 mN when the flat indenter 1 is pulled back. Measure the distance between Let the said distance be the displacement amount (unit: micrometer) in the 50th load-unload cycle.

  Here, “surface” indicates a position where the load is 0 mN at the end of unloading of the previous load-unload cycle.

  The displacement rate is calculated from the displacement amount in the 10th load-unload cycle measured by the above method and the displacement amount in the 50th load-unload cycle.

  As described above, the force (load) applied to the measurement sample 2 at the time of measurement of the “displacement amount in the load-unload cycle” and the “displacement rate” is as small as 1 mN. Even when the measurement sample 2 is formed from the laminated separator for the secondary battery, the load is applied to the porous layer which is the surface layer of the laminated separator for the non-aqueous electrolyte secondary battery. That is, regardless of whether the measurement sample 2 is formed of the porous layer or the laminated separator for a non-aqueous electrolyte secondary battery, a load is applied to the porous layer, As a result, the “displacement amount in the load-unload cycle” and the “displacement rate” in the porous layer are measured.

  The insulating porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention is, in a non-aqueous electrolyte secondary battery, in contact with an electrode as a member constituting a laminated separator for a non-aqueous electrolyte secondary battery. Alternatively, it may be laminated on the electrode and positioned between the electrode and the separator for the non-aqueous electrolyte secondary battery.

  In the non-aqueous electrolyte secondary battery, the active material (positive electrode active material and negative electrode active material) of the electrode changes in volume during charge and discharge, and the electrode (positive electrode and negative electrode) also expands and contracts with charge and discharge. Therefore, when the charge and discharge cycle is repeated, the porous layer is repeatedly subjected to stress (load) due to the expansion of the electrode, and the load and unloading due to the contraction of the electrode.

  When the load-unload cycle is repeated multiple times on the porous layer, the porous layer is plastically deformed by the repeatedly applied load. Therefore, when the load-unload cycle is repeated, the distance for pulling back the above-mentioned planar indenter 1 gradually decreases, particularly when unloading, and the amount of displacement in the load-unload cycle decreases.

  Therefore, in the porous layer according to the embodiment of the present invention, the lower limit of the displacement rate is 100%.

  In the porous layer according to the embodiment of the present invention, the displacement ratio of less than 115% indicates that the degree of plastic deformation of the porous layer is small when the long-term charge and discharge cycle is repeated. When the degree of the plastic deformation is large, the difference between the expansion and contraction of the electrode in the case of repeating a long charge and discharge cycle and the deformation of the porous layer becomes large, so that the space between the porous layer and the electrode becomes Occur. In that case, products and gases derived from the decomposition of the electrolytic solution and the like may be accumulated in the space between the above-described porous layer and the electrode, and battery characteristics such as cycle characteristics may be degraded. If the displacement rate is less than 115%, it is possible to suppress the generation of such a void and the deterioration of the battery characteristics. From such a viewpoint, the displacement rate is preferably 114% or less, more preferably 110% or less.

  On the other hand, when the displacement rate becomes a low value, it means that the displacement amount of the porous layer hardly changes even when the charge and discharge cycle is repeated.

  As described above, in the non-aqueous electrolyte secondary battery, products, gases and the like derived from the decomposition of the electrolyte and the like are generated. And these increase irreversibly. If the displacement rate is too low, the porous layer is hardly plastically deformed, so that the stress generated as a result of the generation of the product and gas is permanently applied to the electrode and the porous layer. As a result, the electrode structure may be changed, and battery characteristics such as cycle characteristics may be degraded. From such a viewpoint, the displacement rate is preferably 103% or more, more preferably 105% or more.

  In the porous layer according to an embodiment of the present invention, “displacement amount in the tenth load-unload cycle” is preferably 0.05 μm or more and 0.20 μm or less, and 0.08 μm or more and 0.15 μm or less More preferable. Further, in the porous layer according to one embodiment of the present invention, “displacement amount in the 50th load-unload cycle” is preferably 0.05 μm or more and 0.20 μm or less, and 0.08 μm or more and 0.15 μm The following are more preferable.

  The porous layer according to an embodiment of the present invention may be laminated on at least one surface of a substrate. As said base material, the base material (Hereafter, it is also mentioned a "porous base material") and an electrode which comprise the lamination | stacking separator for non-aqueous-electrolyte secondary batteries can be mentioned. As said porous base material, a polyolefin porous film can be mentioned, for example.

  The porous layer according to an embodiment of the present invention can be preferably used as a member constituting a laminated separator for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention described later. That is, the porous layer according to an embodiment of the present invention is laminated on one side or both sides of a polyolefin porous film as a porous substrate, thereby a non-aqueous electrolyte secondary battery according to an embodiment of the present invention Can form a laminated separator.

  The porous layer which concerns on one Embodiment of this invention contains a thermoplastic resin. The porous layer is a layer having a large number of pores inside and having a structure in which these pores are connected, and gas or liquid can pass from one side to the other side. In addition, when the porous layer according to an embodiment of the present invention is used as a member constituting a laminated separator for a non-aqueous electrolyte secondary battery, the porous layer is an electrode and the outermost layer of the laminated separator. It can be a contact layer.

<Thermoplastic resin>
The thermoplastic resin contained in the porous layer is preferably insoluble in the electrolyte of the battery, and preferably electrochemically stable in the use range of the battery. Specific examples of the thermoplastic resin include polyolefins such as polyethylene, polypropylene, polybutene, and ethylene-propylene copolymer; polyvinylidene fluoride (PVDF), polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene Copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, fluorine Vinylidene fluoride-trichloroethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, and ethylene-tetrafluroethylene copolymer Fluorine-containing resins such as ethylene copolymer; fluorine-containing rubbers having a glass transition temperature of 23 ° C. or less among the above-mentioned fluorine-containing resins; aromatic polymers; polycarbonates; polyacetals; styrene-butadiene copolymers and their hydrides and methacryls Acid ester copolymer, acrylonitrile-acrylic acid ester copolymer, styrene-acrylic acid ester copolymer, rubber such as ethylene propylene rubber, polyvinyl acetate; melting point or glass transition temperature of polysulfone, polyester etc. is 180 ° C or more Resins; water-soluble polymers such as polyvinyl alcohol, polyethylene glycol, cellulose ether, sodium alginate, polyacrylic acid, polyacrylamide, polymethacrylic acid and the like.

  The thermoplastic resin contained in the porous layer according to an embodiment of the present invention is preferably an aromatic polymer. Here, the "aromatic polymer" refers to a polymer in which an aromatic ring is contained in a structural unit constituting a main chain. That is, it means that the aromatic compound is contained in the raw material monomer of the said thermoplastic resin.

  Specific examples of the aromatic polymer include aromatic polyamide, aromatic polyimide, aromatic polyester, aromatic polycarbonate, aromatic polysulfone, and aromatic polyether. As the above-mentioned aromatic polymer, aromatic polyamide, aromatic polyimide and aromatic polyester are preferred. The aromatic polymer is preferably a wholly aromatic polymer having no aliphatic carbon in its main chain.

  In the present specification, the general name of a polymer represents the main bonding mode of the polymer. For example, when the polymer contained in the thermoplastic resin in the present invention is an aromatic polymer referred to as an aromatic polyester, at least 50% of the number of main chain bonds in the molecule in the aromatic polymer is an ester bond. It represents that there is. In the aromatic polymer referred to as the above-mentioned aromatic polyester, other bonds (for example, an amide bond, an imide bond, etc.) other than an ester bond may be included in the bond constituting the main chain.

  The thermoplastic resin contained in the porous layer according to an embodiment of the present invention may be of one type or a mixture of two or more types of resins.

  As aromatic polyamides, wholly aromatic polyamides such as para-aramid and meta-aramid, semi-aromatic polyamides, 6T nylons, 6I nylons, 8T nylons, 10T nylons, and modified products thereof, or copolymers thereof, etc. may be mentioned. Be

  The aromatic polyimide is preferably a wholly aromatic polyimide prepared by condensation polymerization of an aromatic diacid anhydride and an aromatic diamine. Specific examples of the dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-diphenyl sulfone tetracarboxylic acid dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid Acid dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane, 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride etc. are mentioned. Specific examples of the diamine include oxydianiline, paraphenylene diamine, benzophenone diamine, 3,3'-methylenedianiline, 3,3'-diaminobenzophenone, 3,3'-diaminodiphenyl sulfone, 1,5'- Although a naphthalene diamine etc. are mentioned, this invention is not limited to these. In the present invention, a solvent-soluble polyimide can be suitably used. As such a polyimide, the polyimide of the polycondensate of 3,3 ', 4,4'- diphenyl sulfone tetracarboxylic acid dianhydride and aromatic diamine is mentioned, for example.

Examples of the aromatic polyester include those shown below. Preferably, these aromatic polyesters are wholly aromatic polyesters.
(1) A polymer obtained by polymerizing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and an aromatic diol,
(2) A polymer obtained by polymerizing the same or different aromatic hydroxycarboxylic acid,
(3) A polymer obtained by polymerizing an aromatic dicarboxylic acid and an aromatic diol,
(4) A polymer obtained by polymerizing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and an aromatic amine having a phenolic hydroxyl group,
(5) A polymer obtained by polymerizing an aromatic dicarboxylic acid and an aromatic amine having a phenolic hydroxyl group,
(6) A polymer obtained by polymerizing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and an aromatic diamine.
(7) A polymer obtained by polymerizing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, an aromatic diamine, and an aromatic diol,
(8) A polymer obtained by polymerizing an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, an aromatic amine having a phenolic hydroxyl group, and an aromatic diol.

  Among the above-mentioned aromatic polyesters, aromatic polyesters of the above (4) to (7) or (8) are preferable from the viewpoint of solubility in a solvent. By being excellent in the solubility to a solvent, productivity of a porous layer can be improved.

  In addition, in place of these aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic diamines and aromatic amines having a phenolic hydroxyl group, their ester-forming derivatives or amide-forming derivatives are used. It is also good.

  Here, as ester-forming derivatives or amide-forming derivatives of carboxylic acids, for example, derivatives with high reactivity such as acid chlorides and acid anhydrides in which the carboxyl group promotes polyester formation reaction or polyamide formation reaction And those in which the carboxyl group forms an ester or amide with an alcohol, ethylene glycol, an amine or the like which forms a polyester or polyamide by transesterification or transamidation.

  Moreover, as ester-forming derivative of phenolic hydroxyl group, what the phenolic hydroxyl group forms ester with carboxylic acids etc. is mentioned so that polyester may be produced | generated by transesterification, for example.

  Further, as an amide forming derivative of an amino group, for example, those forming an amide with a carboxylic acid which forms a polyamide by a transamidation reaction and the like can be mentioned.

  In addition, aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol and aromatic amine having a phenolic hydroxyl group, and aromatic diamine are methyl group, ethyl, as long as the ester forming property or the amide forming property is not inhibited. It may be substituted by an alkyl group such as a group, or an aryl group such as a phenyl group.

  Although the following can be illustrated as a repeating structural unit of said wholly aromatic polyester, It is not limited to these.

  Repeating structural units derived from aromatic hydroxycarboxylic acids:

  The above-mentioned repeating structural unit may be substituted by an alkyl group or an aryl group.

  Repeating structural units derived from aromatic dicarboxylic acids:

  The above-mentioned repeating structural unit may be substituted by an alkyl group or an aryl group.

  Repeating structural units derived from aromatic diols:

  The above-mentioned repeating structural unit may be substituted by an alkyl group or an aryl group.

  Repeating structural units derived from aromatic amines having phenolic hydroxyl groups:

  The above-mentioned repeating structural unit may be substituted by an alkyl group or an aryl group. In addition, part or all of the hydrogen atoms bonded to the nitrogen atom may be substituted with an alkyl group, an acyl group or the like.

  Repeating structural units derived from aromatic diamines:

  The above repeating structural unit may be substituted by a halogen atom, an alkyl group or an aryl group.

  In addition, as an alkyl group which may be substituted by the repeating structural unit, a C1-C10 alkyl group is normally used, for example, Especially, a methyl group, an ethyl group, a propyl group or a butyl group is preferable. As an aryl group which may be substituted by the repeating structural unit, for example, an aryl group having a carbon number of 6 to 20 is usually used, and a phenyl group is particularly preferable. In addition, part or all of the hydrogen atoms bonded to the nitrogen atom may be substituted with an alkyl group, an acyl group or the like. As a halogen atom which may be substituted by the repeating structural unit, a fluorine atom, a chlorine atom, a bromine atom is mentioned, for example.

From the viewpoint of further improving the heat resistance of the non-aqueous electrolyte laminate separator according to one embodiment of the present invention, the aromatic polyester is any of (A ₁ ), (A ₃ ), (B ₁ ), (B ₂ ) or (A) preferably contains a repeating unit represented by B ₃₎ expression.

  Here, the following (a) to (d) may be mentioned as preferable combinations of the structural units containing the above-mentioned repeating units.

(A):
A combination of the above repeating structural units (A ₁ ), (B ₂ ) and (D ₁ ),
A combination of the above repeating structural units (A ₃ ), (B ₂ ) and (D ₁ ),
A combination of the above repeating structural units (A ₁ ), (B ₁ ), (B ₂ ) and (D ₁ ),
A combination of the above repeating structural units (A ₃ ), (B ₁ ), (B ₂ ) and (D ₁ ),
A combination of the above repeating structural units (A ₃ ), (B ₃ ) and (D ₁ ), or
A combination of the above repeating structural units (B ₁ ), (B ₂ ) or (B ₃ ) and (D ₁ ).

(B): In each of the combination of the above (a), by substituting a part or all of _{(D 1)} to _{(D 2)} in combination.

(C) A combination in which a portion of (A ₁ ) is replaced with (A ₃ ) in each of the combinations of (a) above.

(D) A combination in which part or all of (D ₁ ) is substituted with (C ₁ ) or (C ₃ ) in each of the combinations of (a) above.
(E): A combination in which part or all of (D ₁ ) is replaced with (E ₁ ) or (E ₅ ) in each of the combinations of the above (a).

  More preferable combination is 10 to 50 mol% of a repeating structural unit derived from at least one compound selected from the group consisting of p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid, 4-hydroxyaniline and 4, 10 to 50 mol% of a repeating structural unit derived from at least one compound selected from the group consisting of 4'-diaminodiphenyl ether, and a repeating structural unit derived from at least one compound selected from the group consisting of terephthalic acid and isophthalic acid It is more preferable to contain 10 to 50 mol%, 10 to 19 mol% of repeating structural units derived from hydroquinone, and further, 10 to 35 mol% of repeating structural units derived from 4-hydroxyaniline, repeating derived from isophthalic acid Containing 20 to 45 mol% of structural units Theft is particularly preferred.

  As a method of preparing the above-mentioned thermoplastic resin, methods known to those skilled in the art can be used without particular limitation. As an example of the method of preparing the thermoplastic resin, a method of preparing an aromatic polyester is exemplified below.

  As a method for preparing an aromatic polyester, for example, an aromatic hydroxycarboxylic acid, an aromatic diol, an aromatic amine having a phenolic hydroxyl group, an aromatic diamine is acylated with an excess amount of fatty acid anhydride (acylation reaction), There is a method of obtaining an acylated product, and polymerizing the obtained acylated product by transesterification / transesterification with an aromatic hydroxycarboxylic acid and / or an aromatic dicarboxylic acid.

  In the acylation reaction, it is preferable that the addition amount of fatty acid anhydride is 1.0 to 1.2 times equivalent of the total of phenolic hydroxyl group and amino group.

  The acylation reaction is preferably performed at 130 to 180 ° C. for 5 minutes to 10 hours, and more preferably at 140 to 160 ° C. for 10 minutes to 3 hours.

  The fatty acid anhydride used in the acylation reaction is not particularly limited, and examples thereof include acetic anhydride, propionic anhydride, butyric anhydride, butyric anhydride and the like, and these may be used as a mixture of two or more types. . Acetic anhydride is preferable from the viewpoint of price and operability.

  In the polymerization by ester exchange / amide exchange, it is preferable that the acyl group of the acylated product is 0.8 to 1.2 times equivalent of the carboxyl group. The polymerization temperature is preferably 400 ° C. or less, more preferably 350 ° C. or less.

  The polymerization by the acylation reaction, transesterification and transamidation may be carried out in the presence of a catalyst. As the above-mentioned catalyst, conventionally known catalysts for polymerization of polyester can be used.

  Polymerization by ester exchange / amide exchange is usually carried out by melt polymerization, but melt polymerization and solid phase polymerization may be used in combination. The solid phase polymerization can be carried out by a known solid phase polymerization method after taking out the polymer from the melt polymerization step, solidifying and pulverizing it into a powder or flake form. Specifically, for example, a heat treatment in a solid phase at 20 to 350 ° C. for 1 to 30 hours in an inert atmosphere such as nitrogen can be mentioned. After solid phase polymerization, the obtained aromatic polyester may be used by pelletizing by a known method.

  The thermoplastic resin contained in the porous layer according to an embodiment of the present invention may be, for example, a mixture of the above-mentioned aromatic polyester and aromatic polyamide. In the above mixture of aromatic polyester and aromatic polyamide, when the total weight of the aromatic polyester and the aromatic polyamide is 100% by weight, the weight of the aromatic polyester is 20% by weight or more and 75% by weight or less Preferably, it is 25% by weight or more and 50% by weight or less.

  Examples of the aromatic polyamide contained in the above-mentioned thermoplastic resin include para-aramid and meta-aramid, and para-aramid is more preferable.

  Although it does not specifically limit as a preparation method of the said aromatic polyamide, The condensation polymerization method of para-oriented aromatic diamine and para-oriented aromatic dicarboxylic acid halide is mentioned. In that case, the resulting aromatic polyamide has an amide bond at the para-position of the aromatic ring or an orientation position according thereto (eg, 4,4'-biphenylene, 1,5-naphthalene, 2,6-naphthalene, etc.) It consists essentially of repeating units joined in opposite orientations, coaxially or in parallel, and specifically, poly (paraphenylene terephthalamide), poly (parabenzamide), poly (4,4 '-Benzanilide terephthalamide), poly (para-phenylene-4,4'-biphenylene dicarboxylic acid amide), poly (para-phenylene-2,6-naphthalene dicarboxylic acid amide), poly (2-chloro-paraphenylene terephthalamide) Para, such as para-phenylene terephthalamide / 2,6-dichloro-p-phenylene terephthalamide copolymer Para-aramid having a structure conforming to the direction type or para type are exemplified.

Further, as a specific method of preparing a solution of poly (paraphenylene terephthalamide) (hereinafter referred to as PPTA) as an aromatic polyamide, for example, the methods shown in the following (1) to (4) can be mentioned.
(1) Charge N-methyl-2-pyrrolidone (hereinafter referred to as NMP) into a dried flask, add calcium chloride dried at 200 ° C. for 2 hours, raise the temperature to 100 ° C., and complete the above calcium chloride Let it dissolve.
(2) The temperature of the solution obtained in (1) is returned to room temperature, paraphenylene diamine (hereinafter abbreviated as PPD) is added, and then the above PPD is completely dissolved.
(3) While maintaining the temperature of the solution obtained in (2) at 20 ± 2 ° C., terephthalic acid dichloride (hereinafter referred to as TPC) is divided into 10 portions and added every about 5 minutes.
(4) The solution obtained in (3) is aged for 1 hour while keeping the temperature at 20 ± 2 ° C., and stirred for 30 minutes under reduced pressure to remove air bubbles to obtain a solution of PPTA.

<Filler>
The porous layer according to an embodiment of the present invention preferably further contains a filler. The said filler is an insulating thing and may be chosen from the organic powder, an inorganic powder, or these mixtures as a material.

  Examples of the organic powder include styrene, vinyl ketone, acrylonitrile, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, glycidyl acrylate, methyl acrylate and the like alone or in combination of two or more types of copolymers; Fluorinated resins such as fluorinated ethylene hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride; melamine resins; urea resins; polyolefins; powders consisting of organic substances such as polymethacrylates . The organic powders may be used alone or in combination of two or more. Among these organic powders, polytetrafluoroethylene powder is preferable in terms of chemical stability.

  Examples of the above-mentioned inorganic powder include powders consisting of inorganic substances such as metal oxides, metal nitrides, metal carbides, metal hydroxides, carbonates, and sulfates, and specific examples thereof include alumina, silica, The powder which consists of titanium dioxide, aluminum hydroxide, or calcium carbonate etc. is mentioned. The inorganic powders may be used alone or in combination of two or more. Among these inorganic powders, alumina powder is preferable in terms of chemical stability. Here, it is more preferable that all of the particles constituting the filler be alumina particles, and even more preferably, all the particles constituting the filler be alumina particles, and some or all of the particles are substantially spherical. Is an embodiment. In the present invention, the substantially spherical alumina particles include spherical particles.

  In the present invention, although the content of the filler in the porous layer according to the embodiment of the present invention depends on the specific gravity of the material of the filler, for example, when all the particles constituting the filler are alumina particles The weight of the filler is usually 20% by weight or more and 95% by weight or less, preferably 30% by weight or more and 90% by weight or less based on the total weight of the porous layer. These ranges can be appropriately set by the specific gravity of the material of the filler.

  The shape of the filler in the present invention may be substantially spherical, plate-like, columnar, needle-like, whisker-like, fibrous or the like, and any particles can be used, but it is easy to form uniform pores, It is preferable that it is a substantially spherical particle. The average particle diameter of the particles constituting the filler is preferably 0.01 μm or more and 1 μm or less from the viewpoint of strength characteristics and smoothness of the porous layer. Here, as the average particle size, a value measured from a scanning electron micrograph is used. Specifically, 50 particles are arbitrarily extracted from the particles photographed in the photograph, the particle diameter of each is measured, and the average value is used.

<Physical Properties of Porous Layer>
The following description of the physical properties of the porous layer indicates at least the physical properties of the porous layer in contact with the positive electrode in the non-aqueous electrolyte secondary battery when the porous layer is laminated on both sides of the substrate. For example, in the case where the porous layer is laminated on both sides of the porous substrate, the porous layer laminated on the surface of the porous substrate facing the positive electrode in the case of a non-aqueous electrolyte secondary battery Indicates at least physical properties.

  The thickness may be determined in consideration of the thickness of the laminated separator for non-aqueous electrolyte secondary batteries to be produced and the size (thickness) of the non-aqueous electrolyte secondary batteries, but one side or both sides of the porous substrate When the porous layer is laminated, the thickness of the porous layer is preferably 0.5 μm to 15 μm (per one side), and more preferably 2 μm to 10 μm (per one side).

  In the laminated separator for a non-aqueous electrolyte secondary battery provided with the porous layer, the internal short circuit due to battery breakage or the like is sufficient that the film thickness of the porous layer is 1 μm or more (0.5 μm or more on one side) It is preferable from the viewpoint of maintaining the amount of electrolyte held in the porous layer. On the other hand, that the film thickness of the porous layer is 30 μm or less in total on both sides (15 μm or less on one side), ions such as lithium ions in the whole area of the laminated separator for non-aqueous electrolyte secondary battery comprising the porous layer Increase in the resistance of the positive electrode when the charge / discharge cycle is repeated, and the decrease in rate characteristics and cycle characteristics can be prevented, and the increase in the distance between the positive electrode and the negative electrode is suppressed. It is preferable at the surface which can prevent the enlargement of a water-electrolyte secondary battery.

  25%-80% are preferable, and, as for the porosity of the porous layer which concerns on one Embodiment of this invention, 30%-75% are more preferable. The porosity of the porous layer is calculated, for example, from the specific gravity and volume of the porous layer. That the porosity is in the above-mentioned range is preferable from the viewpoint of ion permeability of the obtained porous layer and the laminated separator for a non-aqueous electrolyte secondary battery including the porous layer.

The porosity of the porous layer according to one embodiment of the present invention is, for example, calculated and measured by the following method, film thickness [μm], weight per unit area [g / m ² ] and true density [g / m ^3] It is obtained from
(Measurement of film thickness)
The film thickness of the porous base material used for the laminated separator for non-aqueous electrolyte secondary batteries and the laminated separator for non-aqueous electrolyte secondary batteries according to JIS standard (K 7130-1992), manufactured by Mitutoyo Co., Ltd. Measure using a precision digital length measuring machine. The film thickness of the insulating porous layer for non-aqueous electrolyte secondary batteries is calculated from the difference between the obtained film thickness of the laminated separator for non-aqueous electrolyte secondary batteries and the porous substrate.
(Weight basis weight)
A square having a side length of 8 cm is cut out as a sample from the laminated separator for a non-aqueous electrolyte secondary battery, and the weight W ₂ (g) of the sample is measured. A square having a side length of 8 cm is cut out as a sample from the porous base material used for the laminated separator for the non-aqueous electrolyte secondary battery, and the weight W ₁ (g) of the sample is measured. Then, the weight per unit area of the insulating porous layer for the non-aqueous electrolyte secondary battery is calculated according to the following formula (2).
Formula (2): Weight basis weight (g / m ² ) = (W ₂ −W ₁ ) / (0.08 × 0.08)
(True density)
The porous layer in the laminated separator for a non-aqueous electrolyte secondary battery is cut into 4 mm square to 6 mm square and vacuum dried at 30 ° C. or less for 17 hours, and then using a dry automatic densitometer (AccuPye II 1340 manufactured by Micromeritex Co., Ltd.) Measure true density by helium gas replacement method.

From the film thickness [μm], the weight basis weight [g / m ² ] and the true density [g / m ³ ] obtained as described above, the porosity is calculated according to the following equation.
Formula: Porosity of porous layer [%] = [1− (weight of porous layer [g / m ² ]) / {(porous film thickness [μm]) × 10 ⁻⁶ × (porous layer) True density of [g / m ³ ])}] × 100
The air permeability of the porous layer according to one embodiment of the present invention is 30 seconds / 100 cc to 300 seconds / 100 cc from the viewpoint of ion permeability of the laminated separator for non-aqueous electrolyte secondary batteries including the porous layer. Is preferably, and more preferably 50 seconds / 100 cc to 250 seconds / 100 cc. When the air permeability is in the above range, the ion permeability of the porous layer can be kept good, and as a result, the resistance value of the non-aqueous electrolyte secondary battery including the porous layer Battery characteristics can be improved.

<Method of producing porous layer>
As a method for producing a porous layer according to an embodiment of the present invention, for example, a coating for forming a porous layer by dissolving the thermoplastic resin in a solvent and optionally dispersing the filler There is a method of depositing a porous layer according to an embodiment of the present invention by preparing a working fluid, coating the coating fluid on a substrate, and drying it. In addition, the porous base material (polyolefin porous film) mentioned later, or an electrode etc. can be used for a base material.

  The solvent (dispersion medium) is not particularly limited as long as it can dissolve the thermoplastic resin uniformly and stably and can disperse the filler uniformly and stably without adversely affecting the base material. Specific examples of the solvent (dispersion medium) include N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and the like. The solvent (dispersion medium) may be used alone or in combination of two or more.

  The coating liquid may be formed by any method as long as it can satisfy the conditions such as the resin solid content (resin concentration) and the amount of filler necessary to obtain a desired porous layer. Specifically, a method of adding and dispersing a filler in a solution in which the above-mentioned thermoplastic resin is dissolved in a solvent (dispersion medium) can be mentioned. When the filler is added, the filler can be dispersed in the solvent (dispersion medium) using a conventionally known disperser such as a three-one motor, a homogenizer, a media type disperser, or a pressure type disperser.

  As a method of coating a coating liquid on a base material, known coating methods such as a knife, a blade, a bar, a gravure, a die and the like can be used.

  The solvent (dispersion medium) is generally removed by drying. The drying method may, for example, be natural drying, air drying, heat drying, or reduced pressure drying, but any method may be used as long as the solvent (dispersion medium) can be sufficiently removed. Moreover, after replacing the solvent (dispersion medium) contained in a coating liquid with another solvent, you may dry. Specifically, as a method of replacing the solvent (dispersion medium) with another solvent and then removing it, specifically, there is a method of substituting, depositing with a low boiling point poor solvent such as water, alcohol or acetone, and drying.

  The method of controlling the displacement ratio of the porous layer according to an embodiment of the present invention in the range of 100% or more and less than 115% is not particularly limited. For example, the production conditions of the porous layer are adjusted to suitable conditions. Can be mentioned. Moreover, the method of mixing and using 2 or more types of resin in which characteristics differ as a thermoplastic resin contained in a porous layer is mentioned.

  As a suitable manufacturing condition, the method of adjusting the range of the resin concentration in the said coating liquid to 4 weight% or more and less than 20 weight% is mentioned, for example. The more preferable resin concentration is 5% by weight or more and 15% by weight or less. If the resin concentration is lower than the above range, the resin deposition rate in the solvent removal process will be slow, and the precipitated resin will become large, and the structure as a whole will become uneven, and as a result, plastic deformation tends to occur easily. On the other hand, when the resin concentration is higher than the above range, dispersion failure of the coating liquid occurs, the structure as a whole becomes nonuniform, and as a result, plastic deformation tends to occur easily.

  When two or more kinds of resins having different characteristics are mixed and used for the porous layer, the tendency that the compatibility and deformability of the resins constituting the porous layer can be suppressed as compared with the case where only one type is used is there. As a result, the degree of plastic deformation of the porous layer tends to decrease.

  In addition, as a thermoplastic resin contained in the porous layer, a porous layer is obtained by using a resin consisting of only a rigid para-oriented monomer and a thermoplastic resin using an appropriate amount of a meta-oriented monomer as a monomer. It is possible to impart appropriate flexibility while maintaining the rigidity of the above, and suppress the possibility of plastic deformation of the obtained porous layer, and control the above-mentioned displacement rate in the range of 100% or more and less than 115%. You can also

[Second Embodiment: Laminated Separator for Nonaqueous Electrolyte Secondary Battery]
A laminated separator for a non-aqueous electrolyte secondary battery according to Embodiment 2 of the present invention includes a polyolefin porous film and a porous layer according to Embodiment 1 of the present invention. Preferably, the laminated separator for a non-aqueous electrolyte secondary battery according to Embodiment 2 of the present invention comprises the polyolefin porous film and the Embodiment 1 of the present invention laminated on at least one surface of the polyolefin porous film. Such a porous layer is included.

  A laminated separator for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention is provided with an insulating porous layer for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention. The effect of improving the cycle characteristics of the electrolyte secondary battery is exhibited.

<Polyolefin porous film>
The polyolefin porous film in one embodiment of this invention is a porous film which has polyolefin resin as a main component. Moreover, it is preferable that the said porous film is a microporous film. That is, the above-mentioned porous film has a structure having pores connected to the inside thereof, and is mainly composed of a polyolefin resin which is permeable to gas or liquid from one surface to the other surface. The porous film may be formed from one layer or may be formed from a plurality of layers.

With a porous film containing a polyolefin resin as a main component, the proportion of the polyolefin resin component in the porous film is usually 50% by volume or more, preferably 90% by volume, of the entire material constituting the porous film. Above, more preferably, it means that it is 95% by volume or more. The polyolefin resin contained in the polyolefin porous film preferably contains a high molecular weight component having a weight average molecular weight in the range of 5 × 10 ⁵ to 15 × 10 ⁶ . By including a polyolefin resin having a weight average molecular weight of 1,000,000 or more as the polyolefin resin of the porous film, the polyolefin porous film, and the non-aqueous electrolyte secondary battery comprising the polyolefin porous film and the above porous layer It is more preferable because the strength of the entire laminated separator is increased.

  Examples of polyolefin resins include high molecular weight homopolymers obtained by polymerizing ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and the like (eg, polyethylene, polypropylene, polybutene) or co-polymers. Polymers (e.g., ethylene-propylene copolymer) can be mentioned. The polyolefin porous film is a layer containing one of these polyolefin resins and / or a layer containing two or more of these polyolefin resins. In particular, a high molecular weight polyethylene-based resin mainly composed of ethylene is preferable in that it is possible to shut down the excessive current flow at a lower temperature. In addition, a polyolefin porous film does not prevent including components other than polyolefin resin in the range which does not impair the function of the said layer.

  The air permeability of the porous film is usually in the range of 30 seconds / 100 cc to 500 seconds / 100 cc in Gurley value, preferably in the range of 50 seconds / 100 cc to 300 seconds / 100 cc. When the porous film has an air permeability in the above range, a member of a laminated separator for a non-aqueous electrolyte secondary battery comprising the porous film as a separator for a non-aqueous electrolyte secondary battery or a porous layer described later When used as a separator, the separator and the laminated separator can obtain sufficient ion permeability.

  The film thickness of the porous film is preferably 20 μm or less, more preferably 16 μm or less, and still more preferably 11 μm or less, because the thinner the film thickness, the higher the energy density of the battery. In addition, from the viewpoint of film strength, 4 μm or more is preferable. That is, the film thickness of the porous film is preferably 4 μm or more and 20 μm or less.

  The manufacturing method of a porous film can use a well-known method, and is not specifically limited. For example, as described in Japanese Patent No. 5476844, after adding a filler to a thermoplastic resin and forming a film, a method of removing the filler is mentioned.

Specifically, for example, in the case where the porous film is formed of an ultrahigh molecular weight polyethylene and a polyolefin resin containing a low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, the steps shown below from the viewpoint of production cost. It is preferable to manufacture by the method containing (1)-(4).
(1) 100 parts by weight of ultra high molecular weight polyethylene, 5 parts by weight to 200 parts by weight of low molecular weight polyolefin having a weight average molecular weight of 10,000 or less, and 100 parts by weight to 400 parts by weight of an inorganic filler such as calcium carbonate Obtaining a polyolefin resin composition,
(2) a step of forming a sheet using a polyolefin resin composition,
(3) removing the inorganic filler from the sheet obtained in step (2);
(4) A step of stretching the sheet obtained in the step (3).
In addition, the methods described in the above-mentioned patent documents may be used.

  Moreover, you may use the commercial item which has the above-mentioned characteristic as a porous film in this invention.

<Method of Manufacturing Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
As a method for producing a laminated separator for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention, the same method as the method for producing a porous layer according to an embodiment of the present invention described above can be mentioned. Specifically, a method of using the above-mentioned polyolefin porous film as the above-mentioned substrate is mentioned.

Physical Properties of Laminated Separator for Nonaqueous Electrolyte Secondary Battery
The thinner the film thickness of the laminated separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention, the higher the energy density of the battery can be, but the thinner the film thickness, the lower the strength. There is a limit in manufacturing in order to In consideration of the above matters, the film thickness of the laminated separator for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention is preferably 50 μm or less, more preferably 25 μm or less, and still more preferably 20 μm or less. The film thickness is preferably 5 μm or more.

  The air permeability of the laminated separator for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention is preferably 30 to 1000 seconds / 100 cc in Gurley value, and more preferably 50 to 800 seconds / 100 cc. preferable. Sufficient ion permeability can be obtained when the laminated separator for non-aqueous electrolyte secondary batteries has the above air permeability. When the air permeability exceeds the above range, it means that the laminated structure is rough due to the high porosity of the laminated separator for non-aqueous electrolyte secondary batteries, and as a result, the non-aqueous electrolyte secondary The strength of the laminated separator for battery may be reduced, and the shape stability particularly at high temperatures may be insufficient. On the other hand, when the air permeability is less than the above range, the laminated separator for a non-aqueous electrolyte secondary battery can not obtain sufficient ion permeability, and the battery characteristics of the non-aqueous electrolyte secondary battery are deteriorated. There is something I can do.

  In addition to the above porous film and porous layer, the laminated separator for non-aqueous electrolyte secondary batteries according to the present invention may be any known porous film such as an adhesive layer or a protective layer, if necessary. It may be included in the range which does not impair the purpose of.

Embodiment 3: Member for Nonaqueous Electrolyte Secondary Battery, Embodiment 4: Nonaqueous Electrolyte Secondary Battery
A member for a non-aqueous electrolyte secondary battery according to Embodiment 3 of the present invention is a positive electrode, an insulating porous layer for a non-aqueous electrolyte secondary battery according to Embodiment 1 of the present invention, or an embodiment of the present invention The laminated separator for nonaqueous electrolyte secondary batteries concerning 2 and the negative electrode are arrange | positioned in this order.

  The non-aqueous electrolyte secondary battery according to Embodiment 4 of the present invention is the insulating porous layer for a non-aqueous electrolyte secondary battery according to Embodiment 1 of the present invention, or the non-aqueous electrolyte secondary battery according to Embodiment 2 of the present invention. It includes a laminated separator for a water electrolyte secondary battery.

  The non-aqueous electrolyte secondary battery according to an embodiment of the present invention is, for example, a non-aqueous secondary battery that obtains an electromotive force by doping and dedoping of lithium, and is related to a positive electrode and an embodiment of the present invention A non-aqueous electrolyte secondary battery member can be provided in which the insulating porous layer for non-aqueous electrolyte secondary battery and the negative electrode are stacked in this order. A non-aqueous electrolyte secondary battery according to an embodiment of the present invention is, for example, a non-aqueous secondary battery that obtains an electromotive force by doping and de-doping of lithium, and a positive electrode, and an embodiment of the present invention A non-aqueous electrolyte secondary battery member in which the insulating porous layer for non-aqueous electrolyte secondary battery according to claim 1, the polyolefin porous film, and the negative electrode are laminated in this order, that is, the positive electrode, It may be a lithium ion secondary battery provided with the nonaqueous electrolyte secondary battery member by which the lamination separator for nonaqueous electrolyte secondary batteries concerning one embodiment, and the negative electrode are laminated in this order. The components of the non-aqueous electrolyte secondary battery other than the non-aqueous electrolyte secondary battery separator are not limited to the components described below.

  In the non-aqueous electrolyte secondary battery according to an embodiment of the present invention, in general, the negative electrode and the positive electrode are the porous layer according to an embodiment of the present invention, or the non-aqueous electrolyte according to an embodiment of the present invention A battery element in which an electrolytic solution is impregnated in a structure facing each other through a laminated separator for a secondary battery has a structure in which the battery element is enclosed in an outer package. The non-aqueous electrolyte secondary battery is preferably a non-aqueous electrolyte secondary battery, in particular a lithium ion secondary battery. In addition, dope means occlusion, support, adsorption, or insertion, and means the phenomenon in which a lithium ion enters into the active material of electrodes, such as a positive electrode.

  The non-aqueous electrolyte secondary battery member according to one embodiment of the present invention is the insulating porous layer for non-aqueous electrolyte secondary battery according to one embodiment of the present invention, or the non-aqueous electrolyte according to one embodiment of the present invention Since the laminated separator for electrolyte secondary batteries is provided, the effect that the cycle characteristics of the non-aqueous electrolyte secondary battery can be improved is exhibited. The non-aqueous electrolyte secondary battery according to an embodiment of the present invention is the insulating porous layer for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention, or the non-aqueous electrolyte according to an embodiment of the present invention Since the laminated separator for an electrolytic solution secondary battery is provided, the effect of excellent cycle characteristics can be obtained.

<Positive electrode>
The positive electrode in the non-aqueous electrolyte secondary battery member and the non-aqueous electrolyte secondary battery according to one embodiment of the present invention is particularly limited as long as it is generally used as a positive electrode of a non-aqueous electrolyte secondary battery For example, a positive electrode sheet having a structure in which an active material layer containing a positive electrode active material and a binder resin is formed on a current collector can be used. The active material layer may further contain a conductive agent and a binder.

  Examples of the positive electrode active material include materials capable of doping and dedoping lithium ions. Specific examples of the material include a lithium composite oxide containing at least one transition metal such as V, Mn, Fe, Co and Ni.

  Examples of the conductive agent include carbonaceous materials such as natural graphite, artificial graphite, cokes, carbon black, pyrolytic carbons, carbon fibers, and a sintered body of an organic polymer compound. The conductive agent may be used alone or in combination of two or more.

  Examples of the binder include fluorine resins such as polyvinylidene fluoride, acrylic resins, and styrene butadiene rubber. The binder also has a function as a thickener.

  Examples of the positive electrode current collector include conductors such as Al, Ni and stainless steel. Among them, Al is more preferable because it is easily processed into a thin film and inexpensive.

  As a method for producing a sheet-like positive electrode, for example, a method of press-molding a positive electrode active material, a conductive agent and a binder on a positive electrode current collector; a positive electrode active material, a conductive agent and binder using a suitable organic solvent After the adhesive is formed into a paste, the paste is applied to the positive electrode current collector, dried and then pressurized to be fixed to the positive electrode current collector, and the like.

<Negative electrode>
The negative electrode in the non-aqueous electrolyte secondary battery member and the non-aqueous electrolyte secondary battery according to one embodiment of the present invention is particularly limited as long as it is generally used as a negative electrode of a non-aqueous electrolyte secondary battery However, for example, a negative electrode sheet having a structure in which an active material layer containing a negative electrode active material and a binder resin is formed on a current collector can be used. The active material layer may further contain a conductive agent and a binder.

  As said negative electrode active material, the material which can dope and de-dope lithium ion, lithium metal, lithium alloy, etc. are mentioned, for example. As the said material, carbonaceous material etc. are mentioned, for example. Examples of carbonaceous materials include natural graphite, artificial graphite, cokes, carbon black, and pyrolytic carbons.

  Examples of the negative electrode current collector include Cu, Ni, stainless steel, etc. In particular, in a lithium ion secondary battery, Cu is more preferable because it is difficult to form an alloy with lithium and easily processed into a thin film.

  As a method for producing a sheet-like negative electrode, for example, a method of press-molding a negative electrode active material on a negative electrode current collector; a paste-like negative electrode active material using an appropriate organic solvent, and collecting the paste A method of applying to a current collector, drying and pressing to fix the current collector to a negative electrode current collector; The paste preferably contains the conductive agent and the binder.

<Non-aqueous electrolyte>
The non-aqueous electrolyte in the non-aqueous electrolyte secondary battery according to one embodiment of the present invention is not particularly limited as long as it is a non-aqueous electrolyte generally used for non-aqueous electrolyte secondary batteries, for example, lithium salt A non-aqueous electrolytic solution obtained by dissolving the compound in an organic solvent can be used. Examples of lithium salts include LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiSbF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , Li ₂ B ₁₀ Cl _{2 10} , lower aliphatic carboxylic acid lithium salts, LiAlCl _{4 and the} like. Only one type of lithium salt may be used, or two or more types may be used in combination.

  Examples of the organic solvent constituting the non-aqueous electrolytic solution include carbonates, ethers, esters, nitriles, amides, carbamates, sulfur-containing compounds, and fluorine-containing compounds introduced into these organic solvents. A fluorine organic solvent etc. are mentioned. The organic solvents may be used alone or in combination of two or more.

<A member for a non-aqueous electrolyte secondary battery and a method of manufacturing a non-aqueous electrolyte secondary battery>
As a method of manufacturing a member for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention, for example, the above-mentioned positive electrode, an insulating porous layer for a non-aqueous electrolyte secondary battery according to an embodiment of the present invention There may be mentioned a method of arranging a porous substrate, or a laminated separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention, and a negative electrode in this order.

  In addition, as a method of manufacturing a non-aqueous electrolyte secondary battery according to an embodiment of the present invention, for example, after a member for a non-aqueous electrolyte secondary battery is formed by the above method, a non-aqueous electrolyte secondary battery is produced The member for the non-aqueous electrolyte secondary battery is placed in a container that is the case of the above, and then the inside of the container is filled with the non-aqueous electrolyte, and then the container is decompressed and sealed. The non-aqueous electrolyte secondary battery can be manufactured.

[Measuring method]
The physical properties of the polyolefin porous films described in Examples 1 to 4 and Comparative Examples 1 to 4, insulating porous layers for non-aqueous electrolyte secondary batteries, and laminated separators for non-aqueous electrolyte secondary batteries are shown below. It measured by the method.

<Measurement of film thickness>
In Examples 1 to 4 and Comparative Examples 1 to 4, the thickness of the laminated separator for a non-aqueous electrolyte secondary battery and the thickness of the polyolefin porous film according to JIS Standard (K 7130-1992) It measured using the length measuring machine. Moreover, the film thickness of the insulating porous layer for non-aqueous-electrolyte secondary batteries was computed from the difference of the film thickness of the laminated separator for non-aqueous-electrolyte secondary batteries, and the film thickness of the polyolefin porous film.

<Measurement of porosity>
(Weight basis weight)
A square with a side length of 8 cm was cut out as a sample from the polyolefin porous film, and the weight W ₁ (g) of the sample was measured. Also, the square length 8cm of one side of a laminated separator for a nonaqueous electrolyte secondary battery cut as a sample and weighed W _{2 (g)} of the sample. And the weight per unit area of the insulating porous layer for nonaqueous electrolyte secondary batteries was computed according to the following formulas (1).

Weight basis weight (g / m ² ) = (W ₂ −W ₁ ) / (0.08 × 0.08) (1)
From the film thickness [μm] and weight per unit area [g / m ² ] of the porous layer calculated and measured by the above method, and the true density [g / m ³ ] of the porous layer, the following formula (2 The porosity [%] of the said porous layer was calculated based on 1.).

(Porosity) = [1- (weight basis weight) / {(film thickness) × 10 ⁻⁶ × 1 [m ² ] × (true density)}] × 100 (2)
<Measurement of "displacement amount in load-unload cycle" and "displacement rate"
As shown in FIG. 1, the porous layer was cut into 1 cm square to obtain a measurement sample 2. The sample 2 for measurement is fixed on a sample base using an adhesive (water paste), and a flat indenter 1 (made of diamond) having a diameter of 50 μm is loaded from the surface of the sample 2 for measurement at a speed of 0.4877 mN / sec. It was pushed in to a depth of 1 mN (load). Immediately after that, the planar indenter 1 was pulled back to the position of the surface of the sample 2 for measurement where the load was 0 mN at a speed of 0.4877 mN / sec without hold time (unloading). Here, “load” means the magnitude of stress that the planar indenter 1 receives from the measurement sample 2 when the planar indenter 1 is pressed into the measurement sample 2.

  A load was applied to the measurement sample 2 described above and immediately thereafter, a cycle for removing the load (herein referred to as a load-unload cycle) was repeated 50 times. In the measurement sample 2 in the 10th load-unload cycle, the distance between the depth of depression of the plane indenter 1 and the position of the surface of the measurement sample 2 at which the load is 0 mN when the plane indenter 1 is pulled back. Was measured. The said distance was made into the displacement amount (unit: micrometer) in the 10th load-unload cycle. Similarly, in the sample 2 for measurement in the 50th load-unload cycle, the depth at which the flat indenter 1 is pushed in and the position of the surface of the sample 2 for measurement that results in a load of 0 mN when the flat indenter 1 is pulled back. The distance with was measured. The said distance was made into the displacement amount (unit: micrometer) in the 50th load-unload cycle.

  Here, “surface” indicates a position where the load is 0 mN at the end of unloading of the previous load-unload cycle.

  From the displacement amount in the 10th load-unload cycle and the displacement amount in the 50th load-unload cycle measured by the above-mentioned method, the above displacement ratio: {(displacement amount in 10th load-unload cycle) / (50th load-displacement amount in unloading cycle)} was calculated.

[Cycle characteristics: capacity retention rate]
The capacity retention ratio after 100 cycles of the non-aqueous electrolyte secondary batteries manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 was measured by the method described below, and the cycle characteristics were evaluated.

  With respect to the non-aqueous electrolyte secondary battery not subjected to the charge and discharge cycle manufactured in Examples 1 to 4 and Comparative Examples 1 to 4, a voltage range at 25 ° C .: 4.1 to 2.7 V, a current value; Initial charging / discharging of 4 cycles was performed with 0.2 C (a current value of discharging a rated capacity by a discharge capacity at 1 hour rate in 1 hour as 1 C, the same applies hereinafter) as one cycle.

  The capacity (initial capacity) of the non-aqueous electrolyte secondary battery subjected to the initial charge and discharge was measured.

  Subsequently, one cycle of performing charging / discharging at a constant current of 1 C and a discharge current of 10 C at 55 ° C. is performed on the non-aqueous electrolyte secondary battery after measurement of the initial capacity. , 100 cycles of charge and discharge. The capacity (capacity after 100 cycles) of the non-aqueous electrolyte secondary battery subjected to 100 cycles of charge and discharge was measured.

  The ratio of the capacity after 100 cycles to the initial capacity measured by the above-mentioned method was calculated and used as the capacity retention rate after 100 cycles.

Example 1
<Synthesis of Thermoplastic Resin>
(Synthesis of wholly aromatic polyester)
A wholly aromatic polyester A was synthesized as a thermoplastic resin by the method described below.

  In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer and reflux condenser, 248.6 g (1.8 mol) of 4-hydroxybenzoic acid and 468.6 g (3 of 4-hydroxyacetanilide) 1 mol), 681.1 g (4.1 mol) of isophthalic acid and 110.1 g (1.0 mol) of hydroquinone were charged. Then, after the inside of the reactor is sufficiently replaced with nitrogen gas, the temperature inside the reactor is raised to 150 ° C. in a nitrogen gas flow over 15 minutes, and reflux is maintained for 3 hours while maintaining the temperature (150 ° C.) I did.

  Thereafter, the temperature is raised to 300 ° C. over 300 minutes while distilling off the by-product (acetic acid) to be distilled off and the unreacted acetic anhydride, and the point at which a rise in torque is observed is regarded as completion of the reaction. I took it out. The contents were cooled to room temperature and ground with a grinder to obtain relatively low molecular weight wholly aromatic polyester powder.

  Furthermore, solid phase polymerization was performed by heat-processing this wholly aromatic polyester powder in a nitrogen atmosphere at 290 ° C. for 3 hours.

  The relatively high molecular weight wholly aromatic polyester thus obtained is referred to as aromatic polyester B. 100 g of the above aromatic polyester B was added to 400 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as a solvent, and heated at 100 ° C. for 2 hours to obtain a solution of aromatic polyester B.

(Synthesis of aramid resin)
Aramid resin A was synthesized as a thermoplastic resin by the method described below using a 5-liter separable flask having a stirring blade, a thermometer, a nitrogen inflow tube, and a powder addition port.

  The separable flask was sufficiently dried, 4200 g of NMP was charged, 272.65 g of calcium chloride dried at 200 ° C. for 2 hours was added, and the temperature was raised to 100 ° C. After calcium chloride was completely dissolved, the temperature in the flask was returned to room temperature, 131.91 g of paraphenylenediamine (hereinafter abbreviated as PPD) was added, the PPD was completely dissolved, and a solution was obtained. While maintaining the temperature of this solution at 20 ± 2 ° C., 243.32 g of terephthalic acid dichloride (hereinafter abbreviated as TPC) was added in 10 portions and added every about 5 minutes to the solution. Thereafter, while keeping the temperature of the obtained solution at 20 ± 2 ° C., the solution was aged for 1 hour, stirred for 30 minutes under reduced pressure to remove bubbles, and a solution of aramid resin A was obtained.

<Preparation of coating liquid>
(Aromatic polyester B): (Aramid resin A) = 50 parts by weight: The solution of aromatic polyester B and the solution of aramid resin A are mixed so as to be 150 parts by weight, and further 100 parts by weight of aromatic polyester B Then, 200 parts by weight of alumina powder having an average particle diameter of 0.02 μm and alumina powder having an average particle diameter of 0.3 μm were added. Then, after diluting with NMP so that solid content concentration might be 7.0%, it stirred with a homogenizer, and also the coating liquid 1 was obtained by 50 MPa x 2 times processing with a pressure type dispersing machine.

<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
The obtained coating solution 1 was applied to a porous film of polyethylene which is a polyolefin porous film (thickness 12 μm, porosity 44%) by a doctor blade method, the solid content in the coating solution per square meter 2. It applied so that it might be set to 6 g. The resulting laminate, which is the coated product, is placed in a humidified oven at 60 ° C. and 80% relative humidity for 1 minute, then washed with ion-exchanged water and then dried in an oven at 80 ° C. for non-aqueous electrolyte secondary batteries A laminated separator was obtained. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 1 for a non-aqueous electrolyte secondary battery. The film thickness of the laminated separator 1 for non-aqueous electrolyte secondary batteries was 15.8 μm, and the porosity of the porous layer was 68%.

<Manufacture of non-aqueous electrolyte secondary battery>
Next, a non-aqueous electrolyte secondary battery was produced according to the following using the laminate separator 1 for non-aqueous electrolyte secondary battery produced as described above.

(Production of positive electrode)
A commercially available positive electrode manufactured by applying LiNi _0.5 Mn _0.3 Co _0.2 O ₂ / conductive agent / PVDF (weight ratio 92/5/3) to an aluminum foil was used. In the commercially available positive electrode, the size of the portion where the positive electrode active material layer is formed is 45 mm × 30 mm, and the aluminum foil is made so that a portion where the positive electrode active material layer is not formed with a width of 13 mm remains on the outer periphery. It cut out and set it as the positive electrode. The thickness of the positive electrode active material layer was 58 μm, the density was 2.50 g / cm ³ , and the positive electrode capacity was 174 mAh / g.

(Fabrication of negative electrode)
A commercially available negative electrode manufactured by applying a graphite / styrene-1,3-butadiene copolymer / sodium carboxymethylcellulose (weight ratio 98/1/1) to a copper foil was used. The commercially available negative electrode is a copper foil so that the size of the portion where the negative electrode active material layer is formed is 50 mm × 35 mm, and the portion where the negative electrode active material layer is not formed remains at a width of 13 mm. It cut out and set it as the negative electrode. The thickness of the negative electrode active material layer was 49 μm, the density was 1.40 g / cm ³ , and the negative electrode capacity was 372 mAh / g.

(Assembly of non-aqueous electrolyte secondary battery)
Using the positive electrode, the negative electrode, and the laminated separator 1 for a non-aqueous electrolyte secondary battery, a non-aqueous electrolyte secondary battery was manufactured by the method described below.

  A member for a non-aqueous electrolyte secondary battery was obtained by laminating (arranging) the positive electrode, the non-aqueous electrolyte secondary battery secondary separator 1, and the negative electrode in this order in a laminate pouch. At this time, the positive electrode and the negative electrode were disposed such that the whole of the main surface in the positive electrode active material layer of the positive electrode was included in the range of the main surface in the negative electrode active material layer of the negative electrode (overlapping the main surface).

Subsequently, the member for a non-aqueous electrolyte secondary battery was placed in a bag in which an aluminum layer and a heat seal layer were laminated, and further, 0.25 mL of the non-aqueous electrolyte was placed in the bag. As the non-aqueous electrolyte, LiPF ₆ is dissolved in a mixed solvent of ethyl methyl carbonate, diethyl carbonate and ethylene carbonate in a volume ratio of 50:20:30 so that the concentration of LiPF ₆ becomes 1 mol / L. A 25 ° C. electrolyte was used. Then, while the inside of the bag was depressurized, the bag was heat sealed to fabricate a non-aqueous electrolyte secondary battery. The design capacity of the non-aqueous electrolyte secondary battery was 20.5 mAh. The non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 1.

Example 2
<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
A solution of aromatic polyester B and a solution of aramid resin A are mixed such that the amount of the aramid resin A is 128 parts by weight with respect to 72 parts by weight of the aromatic polyester B, and the obtained solution is mixed with alumina powder. Coating liquid 2 was obtained in the same manner as in Example 1 except that the resulting dispersion liquid was diluted with NMP so that the solid content concentration was 8.0%. Using the obtained coating liquid 2, a laminated separator for a non-aqueous electrolyte secondary battery was obtained by the same method as in Example 1. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 2 for a non-aqueous electrolyte secondary battery. The film thickness of the non-aqueous electrolyte secondary battery laminated separator 2 was 15.9 μm, and the porosity of the porous layer was 67%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 2 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 2.

[Example 3]
<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
A solution of aromatic polyester B and a solution of aramid resin A are mixed so that the aramid resin A is 100 parts by weight with respect to 100 parts by weight of the aromatic polyester B, and alumina powder is mixed with the obtained solution Coating liquid 3 was obtained in the same manner as in Example 1 except that the resulting dispersion liquid was diluted with NMP so that the solid content concentration was 9.0%. Using the obtained coating liquid 3, a laminate separator for a non-aqueous electrolyte secondary battery was obtained in the same manner as in Example 1. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 3 for a non-aqueous electrolyte secondary battery. The film thickness of the laminated separator 3 for non-aqueous electrolyte secondary batteries was 16.0 μm, and the porosity of the porous layer was 68%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 3 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 3.

Example 4
<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
A solution of aromatic polyester B and a solution of aramid resin A are mixed so that the aramid resin A is 80 parts by weight with respect to 120 parts by weight of the aromatic polyester B, and alumina powder is mixed with the obtained solution A coating liquid 4 was obtained in the same manner as in Example 1 except that the resulting dispersion was diluted with NMP so that the solid content concentration was 10.0%. Using the obtained coating liquid 4, a laminated separator for a non-aqueous electrolyte secondary battery was obtained in the same manner as in Example 1. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 4 for a non-aqueous electrolyte secondary battery. The film thickness of the laminated separator 4 for non-aqueous electrolyte secondary batteries was 15.8 μm, and the porosity of the porous layer was 68%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 4 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 4.

Comparative Example 1
<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
Without using the above aramid resin, a solvent (NMP) is added only to the above aromatic polyester B to adjust the solid content concentration (aromatic polyester B) to 20% by weight, and further to 200 parts by weight of polymer B Then, 200 parts by weight each of alumina powder having an average particle diameter of 0.02 μm and alumina powder having an average particle diameter of 0.3 μm were added to obtain a dispersion. The dispersion liquid was dispersed, mixed and dispersed in the same manner as in Example 1 to obtain a coating liquid 5. Using the obtained coating liquid 5, a laminated separator for a non-aqueous electrolyte secondary battery was obtained in the same manner as in Example 1. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 5 for a non-aqueous electrolyte secondary battery. The film thickness of the non-aqueous electrolyte secondary battery laminated separator 5 was 15.8 μm, and the porosity of the porous layer was 68%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 5 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 5.

Comparative Example 2
<Synthesis of Aramid Resin>
In a 5-liter (l) separable flask having a stirrer, a thermometer, a nitrogen inflow tube, and a powder addition port, 222 g of metaphenylene diamine and 3300 g of NMP were charged and dissolved by stirring. Subsequently, 419 g of isophthalic acid chloride dissolved by heating to 70 ° C. was dissolved in 1000 g of NMP and then added dropwise, and reacted at 23 ° C. for 60 minutes to obtain a 10% aramid resin solution. The resulting aramid resin solution was dried under reduced pressure to obtain a solid of aramid resin C.

<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
The solid of the above aramid resin C, alumina fine particles (manufactured by Sumitomo Chemical Co., Ltd .; trade name "AKP 3000"), and a solvent (a mixed solvent obtained by mixing 40 parts by weight of tripropylene glycol to 60 parts by weight of dimethylacetamide) After the solution is mixed so that the aramid resin is 30 parts by weight with respect to 70 parts by weight of the alumina fine particles, the solvent is added to the obtained mixed solution, and 20 parts by weight of solid content concentration (alumina fine particles + aramid resin) The dispersion was adjusted to be% to obtain a dispersion. And the coating liquid 6 was obtained by the method similar to Example 1 except using the said dispersion liquid.

  The resulting coating solution 6 was applied onto a porous film of polyethylene which is a polyolefin porous film (thickness 12 μm, porosity 44%) by a doctor blade method so that the solid content in the coating solution was 5. per square meter. It applied so that it might be set to 6 g. The resulting coated product, the laminate, is placed in a coagulating bath of water: dimethylacetamide: tripropylene glycol = 50: 30: 20 at 40 ° C. for 1 minute and then washed with ion exchanged water and then at 80 ° C. It was dried in an oven to obtain a laminated separator 6 for a non-aqueous electrolyte secondary battery.

  The film thickness of the laminated separator 6 for electrolyte secondary batteries was 15.3 μm, and the porosity of the porous layer was 50%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 6 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 6.

Comparative Example 3
<Preparation of coating liquid>
A mixture of 100 parts by mass of alumina fine particles (manufactured by Sumitomo Chemical; trade name "AKP-3000") and 6 parts by mass of carboxymethylcellulose (manufactured by Daicel; trade name "1110") so that the solid content is 30% by weight Was added to obtain a mixture. The obtained mixture is stirred and mixed twice under the conditions of 2000 rpm and 30 seconds at room temperature using a rotation / revolution mixer “Awatori Neritaro” (manufactured by Shinky Co., Ltd .; registered trademark), and a coating solution 7 I got

<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
The obtained coating solution was applied onto a porous film of polyethylene which is a polyolefin porous film (thickness: 16.2 μm, porosity: 53%) by the doctor blade method, and the solid content in the coating solution was 6 per square meter. It applied so that it might become .7g. The obtained coated product, which is a laminate, was dried at 80 ° C. for 1 minute to obtain a laminated separator for a non-aqueous electrolyte secondary battery. The obtained laminated separator for a non-aqueous electrolyte secondary battery is referred to as a laminated separator 7 for a non-aqueous electrolyte secondary battery. The film thickness of the laminated separator 7 for non-aqueous electrolyte secondary batteries was 18.8 μm, and the porosity of the porous layer was 50%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 7 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 7.

Comparative Example 4
<Production of Laminated Separator for Nonaqueous Electrolyte Secondary Battery>
An NMP solution of PVDF resin (polyvinylidene fluoride homopolymer) (manufactured by Kleha Co., Ltd .; trade name "L # 7305", weight average molecular weight: 1,000,000) was used as the coating solution 8 and a porous polyethylene film (thick The PVDF resin in the coating solution was applied to a thickness of 5.0 g per square meter by a doctor blade method on a thickness of 12 μm. The coated material obtained was immersed in 2-propanol with the coating film wet, allowed to stand at -25 ° C for 5 minutes, and a laminated porous film was obtained. The obtained layered porous film was dipped in a dipping solvent wet state, further dipped in another 2-propanol, and allowed to stand at 25 ° C. for 5 minutes to obtain a layered porous film. The obtained laminated porous film is dried at 30 ° C. for 5 minutes to obtain a laminated separator 8 for a non-aqueous electrolyte secondary battery. The film thickness of the non-aqueous electrolyte secondary battery laminated separator 8 was 15.5 μm, and the porosity of the porous layer was 65%.

<Manufacture of non-aqueous electrolyte secondary battery>
A non-aqueous electrolyte secondary battery was manufactured in the same manner as Example 1, except that the non-aqueous electrolyte secondary battery laminated separator 8 was used instead of the non-aqueous electrolyte secondary battery laminated separator 1. The manufactured non-aqueous electrolyte secondary battery is referred to as a non-aqueous electrolyte secondary battery 8.

[Conclusion]
The physical property values of laminated separators 1 to 8 for non-aqueous electrolyte secondary batteries manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1 below. Further, the capacity retention ratio after 100 cycles of the non-aqueous electrolyte secondary batteries 1 to 8 manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 is also shown in Table 1 below.

  From the description in Table 1, an embodiment in which the ratio of the displacement amount in the 10th load-unload cycle to the displacement amount in the 50th load-unload cycle (displacement ratio) is 100% or more and less than 115%. The nonaqueous electrolyte secondary battery provided with the insulating porous layer for nonaqueous electrolyte secondary batteries manufactured in 1-4 is manufactured in Comparative Examples 1-4 in which the displacement rate is out of the above range. It was found that the capacity retention rate after 100 cycles was higher and the cycle characteristics were excellent than the non-aqueous electrolyte secondary battery provided with the insulating porous layer for the non-aqueous electrolyte secondary battery.

  From the above-mentioned matters, the insulating porous layer for the non-aqueous electrolyte secondary battery manufactured in Examples 1 to 7 is provided with the insulating porous layer for the non-aqueous electrolyte secondary battery. It has been found that the cycle characteristics of the secondary battery can be improved.

  The insulating porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention has cycle characteristics of a non-aqueous electrolyte secondary battery including the insulating porous layer for the non-aqueous electrolyte secondary battery. It can be improved. Therefore, the insulating porous layer for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention is useful as a member of a non-aqueous electrolyte secondary battery.

1 Plane indenter 2 Sample for measurement

Claims (4)

What is claimed is: 1. An insulating porous layer for a non-aqueous electrolyte secondary battery containing a thermoplastic resin, comprising:
The porosity is 25% or more and 80% or less,
An insulating porous layer for a non-aqueous electrolyte secondary battery, wherein the ratio of the displacement in the 10th load-unload cycle to the displacement in the 50th load-unload cycle is 100% or more and less than 115%. .   A laminated separator for a non-aqueous electrolyte secondary battery comprising a polyolefin porous film and the insulating porous layer for a non-aqueous electrolyte secondary battery according to claim 1.   A positive electrode, an insulating porous layer for a non-aqueous electrolyte secondary battery according to claim 1, or a laminated separator for a non-aqueous electrolyte secondary battery according to claim 2, and a negative electrode are arranged in this order A member for a non-aqueous electrolyte secondary battery.   A non-aqueous electrolyte secondary battery comprising the insulating porous layer for a non-aqueous electrolyte secondary battery according to claim 1 or the laminated separator for a non-aqueous electrolyte secondary battery according to claim 2.